An app for recording working hours, absence planning and expense recording with approval processes could offer the following functions:

1. working time recording:
-Punch clock: employees can record their working hours by punching in and out.
-Project time recording: Times can be assigned to specific projects or tasks.
-Overtime calculation: Automatic calculation of overtime and its management.

2. absence planning:
-Leave requests: Employees can submit vacation requests and track the status of their requests.
-Sick notes: Ability to record and manage sick notes.
-Absence calendar: Overview of all absences in the team or company.

3. expense recording:
-Receipt upload: Employees can upload photos of receipts and submit their expenses digitally.
-Expense report: Automatic calculation and categorization of expenses.
-Approval processes: Supervisors can review and approve or reject expense requests.

4.Approval processes:
-Approval workflows: Defined workflows for the approval of working hours, absences and expenses.
-Notifications: Automatic notifications for new requests or changes in status.
Reports and analyses: Creation of reports to analyze the recorded data and support decision-making.